Aeronautical propeller



Nov. 17, 1931. R. B. BElsEL 1,832,275

AERONAUTICAL PROPELLER Filed April 20. 1926 2 sheets-sheet 1 INVENTOR RE .B.BE|5EL.

ATTO EY Nov. 17, 1931. R. B. BElsEL AERONAUTICAL PROPELLER Filed April 20, 1926 2 Sheets-Sheet 2 INVENTOR REX EEISEL,

s'rTEs PATENT OFFICE REX B. IBEISEL, OF EAST HEMPSTEAD, NEW YORK, ASSIGNOR TO CURTISS AER/DYLAN E &

MOTOR COMPANY, INC., `A CORPORATION OF NEW YORK AERONAUTICAL PROPELLER Application mea Aprn 2o,

My invention relates to metal propellers for aircraft.

An object of the invention is t'o provide an all metal aeronautical propeller in which the propeller blades and the propeller hub portion are separately formed and in which two or more peripheral bearing surfaces are provided on said hub portion against which the inner blade ends bear.

A further object of the invention is to so form and construct the engaging hub and blade portions as to provide for a variation in the pitch angle of the propeller by merely rotating the propeller blades about their respective longitudinal axes, the inner blade ends being fastened to the propeller hub portion in a manner such that by loosening the blade fastening the desired blade adjustment can be obtained.

A further object of the invention is to provide at the joint between each propeller blade and the propeller hub a centering means whereby in adjusting the blades relatively to said hub said blades are held against transverse movement tho freely movable about their respective longitudinally axes as aforesaid.

A still further object of the invention is to provide at each blade and hub joint such markings as will constitute a vernier scale and to further provide for cooperation with each such scale an adjusting pin by means of which accuracy is obtained in correspondingly adjusting the pitch angle of the two or more propeller blades.

Other objects and advantages of the invention will be hereinafter disclosed.

In the drawings, wherein like reference characters denote like or corresponding parts,

Fig. 1 is a front elevation of that portion of the propeller of my invention in the vicinity of the propeller hub;

Fig. 2 is a similar view of the propeller in its entirety;

Fig. 3 is a perspective view of the propeller hub with the angle plates thereof detached and lifted;

Fig. 4 is a section on the line 4-4 of Fig. 1;

1926.- Serial No. 103,295..

Fig. 5 is a side elevation of the propeller hub, partly in section, the section being at right angles to the section of Fig. 4;

Fig. 6 is a fragmentary View of a portion of the Vernier scale;

Fig. 7 isa fragmentary sectional view further illustrating said scale, and

lgig. 8 is a perspective view of the propeller hu In the embodiment of the invention selected for illustration, a two-blade metal propeller is shown. Such showing, however, is merely illustrative, and the invention, if desired, may be equally as well used on and in connection with propellers having three, four or any number of blades. f

The y propeller hub, designated in its en tire ty as 10, is preferably constructed of metal.

It comprises a hub sleeve 11, extended as at 12 at one end, and an integra-1 body portion 13 made as light as it is possible to make it consistent with the required strength. Said body portion 13 is provided with peripheral bearing surfaces 14-14 against which the blades 15-15 of the propeller bear. rlhese bearing surfaces 14, of which there are two, one for each pro eller blade, are substantially Hat and diametrically opposed. At the exact center of each said surface 14 an outwardly projecting lug 16 is provided. These lugs (see Fig. 5) are adapted to iit in recesses 17 formed in the inner ends of the propeller blades.

The blades 15 are preferably formed each from a fiat stock piece of metal blank properly shaped and twisted to the pitch or the blade angle called for by the propeller design. At their respective inner ends said blades 15 bear endwise on the peripheral bearing surfaces 14-14 of the hub and normally (lengthwise such end) parallel the axis of the hub sleeve. Each said blade at its inner end is laterally enlarged by angle plates 18 fastened, one against each face of the inner blade end, by thru bolts 19. These angle plates or pieces together provide at the inner end of each blade 15 a bearing area of substantially the same size and shapevas the peripheral bearing surfaces against which said blade ends bear. Preferably such engaging or bearing surfaces are substantially com- 'tively to the peripheral bearing surfaces of the hub. The lug or projection 16 at each inner blade end centers the propeller blades on Vsaid hub bearing surfaces and during the adjustment of the blades holds them against lateral displacement without interfering in any way with their rotation. Stud bolts 20 penerating the angle piece 18 at opposite sides of the blade ends and engaging inY bolt holes 21 formed in the hub, serve as the fastening means for holding the blade and hub together. After loosening the bolts 20 the blade 15 may be adjusted. The bolt holes 22 in the blade end enlargements or angle pieces are arcuately elongated about the blade axes as centers. The length of these elongated bolt holes 22 determine the degree or extent of adjustment accorded the propeller blades. If desired,

vthru bolts may replace the stud bolts 20 and integral enlargements formed on the inner blade ends may replace the angle pieces 18. Where angle pieces are used, however, the blades are anchored therebetween by ridges 23 engaging in notches 24 formed on the angle pieces and the blades respectively.

.As an aid in effecting adjustment of the lblades l5 relatively to each other and to the hub bearing surfaces 13, a Vernier scale is provided at the joint between each blade and the hub. Markings or grooves 24 formed on each inner blade end, or rather innerblade end enlargement, constitute the movable scale of the vernier, whereas similar markings or grooves 25 formed on the hub bearing surfaces for cooperation with the markings 24 constitute the fixed scale of the vernier. Such grooves or markings 24 and 25 are radially arranged and are carried from the outer edge of the engaging surfaces inwardly toward the blade axes or hub center as shown. By shifting the movable scale relatively to the fixed scale, due to a difference in the number of markings provided for each blade, an accurate blade setting can be readily obtained. If ``desired, thevernier scale may be marked to indicate either fractional or full degree increments of change in the angular setting of the blades. An adjusting pin 26 flanged as at 27 is provided to insure absolute accurac in the operation of the Vernier scale. aid pins engage in the grooves 24 and 25 of the scale and the flanges 27, which are conical, are adapted to engage in arcuate grooves 28-28 which traverse the radial grooves 24 and 25. By inserting the adjusting pin 26 within one or another of the radial holes formed by the registering grooves 24 and 25, a perfect registry and hence a perfect adjustment of each propeller blade is obtained.

A11 aeronautical propeller thus charactering shaft; and in that the manufacturmg v cost of adjustable pitch metal aeronautical propellers is very appreciably reduced.

While I hai'e described my invention in detail in its present preferred embodiment, it'will be obvious to those skilled in the art after understanding my invention, that various changes and modifications may be made therein `Without departing from the spirit or scope thereof. I aim in the appended claims to cover all such modifications and changes.

What I claim is; v

l. An aeronautical propeller including a hub, blades adjustably rotatable about their respective longitudinal axes relatively to said hub and bearing at one end thereon, angle plates fastened to and providing at the inner blade ends a bearing surface substantially complemental to the blade engaging area of the hub, and means for fastening in its adp justed position each said blade to said hub.

' 2. An aeronautical propeller including a hub .provided with two or more peripheral bearing surfaces, a corresponding number of blades bearing at one end on and rotatable about their respective longitudinal axes relatively to said bearing surfaces, the inner end of each blade being of substantially the same width as said hub, angle plates fastened to the inner flat blade ends and ,bearing directly on said peripheral hub bearing surfaces, and

means extending thru the flattened end ofV each angle plate and into the hub for fastening the propeller blades thereto.

3. An aeronautical propeller including a hub, separate and detachable blades adjustably rotatable about their respectivelongitudinal axes extending out from said hub, angle plates fastened to said hub and between which the inner blade ends are anchored, said angle plates being adjustable rotatable with said blades, and a fastening means for said blades extending therethru and thru said angle plates.

4. An aeronautical propeller including a hub provided with two or more peripheral bearing surfaces, separate and detachable blades bearing at their inner ends on and -adjustably rotatable about their'respective longitudinal axes relatively to said bearing surfaces, angle plates, fastened to said hub between which the inner blade ends. are anchored, said angle plates being adjustably llO rotatable with said blades, and means for 7 'H piece metal slab twisted and'shaped at its inner end to bear directly on said peripheral bearing surfaces and to extend at said inner end lengthwise the axis of the hub sleeve, and pairs of angle plates Jfastened to said bear- '.ing surfaces with and between which the inner blade ends are adapted ,to interlock.

6. In a variable pitch aeronautical propeller, a hub, a blade secured to said hub and rotatable about its own longitudinal axis, an attachment cooperating with the inner end of said blade for aiding in positioning it with respect to said hub, a plurality of equally spaced recesses formed in said attachment, a plurality of equally spaced recesses formed in said hub, the distance between adjacent recesses in said hub being diderent from the distance between adjacent recesses formed in said attachment, and a locking element inserted partly in a recess in the hub and partly in a recess in the attachment.

7. In a variable pitch aeronautical propeller, a hub, a blade secured to said hub and rotatable about its own longitudinal axis, an attachment cooperating with the inner end of said blade for aiding in positioning it with respect to said hub, a plurality of equally spaced recesses formed in said attachment, a

. plurality of equally spaced recesses formed in said hub, the distance between adjacent recesses in said hub being different from the distance between adjacent recesses formed in said attachment, and a locking element inserted partly in a recess in the hub and partly in a recess in the attachment and positioned with its longitudinal axis substantially perpendicular to said longitudinal axis of the blade.

8. In a variable pitch propeller, a hub, a blade secured to said hub and rotatable about the longitudinal axis of said blade, an attachment cooperating with the inner end of said blade for aiding in positioning it with respect to said hub, a plurality of equally spaced semi-cylindrical grooves formed in said attachment, a plurality of equally spaced semicylindrical grooves formed in said hub, the distance between adjacent grooves in said hub being different from the distance between adjacent grooves in said attachment, and one of the grooves in said hub cooperating with one of the grooves in said attachment to form a complete cylindrical recess, and a locking a element inserted within said two cooperating grooves.

9. An aeronautical propeller including a hub provided with peripheral bearing surfaces, blades adj ustably rotatable about their respective longitudinal axes relative to said hub and bearing at one end directly thereon, detachable angle plates fastened to each blade end and providing at each said inner blade end a bearing surface substantially complemental to the peripheral bearing surface of said hub, and means for fastening each said blade to said hub in its adjusted position.

10. In a variable pitch aeronautical propeller, a hub having a substantially fiat surface formed thereon, a lug also formed on said hub to protrude above said flat surface, a blade adapted to be secured to said hub and to rotate about its longitudinal axis, said blade having a substantially flat portion at its inner end adapted to it against the flat portion of the hub and having a substantially cylindrical recess adapted to receive said lug, means for securing the innerend of said blade to said hub comprising a pair of locking plates bolted to said blade and to said hub, each of said locking plates having one face substantially at to fit against the flat face of the hub, one of the saidlocking plates having a plurality of equally spaced grooves formed on said flat surface, the fiat surface of the hub also having a plurality of similar equally spaced grooves formed thereon, the distance between two adjacent grooves on the locking plate being unequal to the distance between two adjacent grooves on the hub, one of the grooves in the locking plate being aligned with one of the grooves in the hub to form a unitary substantially cylindrical hole, a depression being formed in the locking plate and a second depression being formed in the hub so that said two depressions align with each other and form a recess positioned substantially perpendicular .to the above mentioned grooves, means, comprising a pin inserted in the aligned grooves and positioned perpendicular to the longitudinal axis of the blade, for locking the blade against rotation about its said longitudinal axis, said pin having a flange thereon for fitting in said recess and for securing said pin against withdrawal.

11. In a variable pitch aeronautical propeller, a hub, a blade adapted to be secured to said hub, means for securing the inner end of said blade to said hub comprising a pair of right angle locking plates bolted to said blade and to said hub.

12. In a variable pitch aeronautical propeller, a hub having a substantially iat bearing surface formed thereon, a blade adapted to be secured to said hub and to rotate about its own longitudinal axis, said blade having a substantially at portion on its inner end adapted to lit against the fiat bearing surface of the hub, means for securing the inner end of said blade to said hub comprising a pair of locking plates adapted to be secured to said blade and to said hub, each of said locking plates having one face substantially flat to fit against the fiat face of the hub, means for securing said locking plates to said blade in such position that the Hat face 4portions of the locking plates shall form a substantial continuation of the flat portion at the inner end of the blade and al1 of said at portions 5 shall combine to fit snugly against the Hat bearing surface formed on the hub, and llielans for securing said locking plates to said u In testimony whereof I hereunto ax my l signature.

REXB, BEISEL. 

